Proposed changes to VIDA requirements, which could see clauses in the existing document being removed, may have far-reaching environmental consequences
Under the current Vessel General Permit (VGP 2013) rules, the US Environmental Protection Agency (EPA) recommends that all newbuild vessel operators endeavour to use seawater‐based systems for their stern tube lubrication to prevent the discharge of oil from these interfaces to the marine environment. But in the revised Vessel Incidental Discharge National Standards of Performance (VIDA) draft there is no mention of seawater as an Environmentally Acceptable Lubricant (EAL).
The proposed VGP changes mention composite bearings but do not state that the composite bearings must be lubricated by seawater to eliminate all risk of pollution.
Calling for a 60‐day extension to the period in which stakeholders can comment on the proposals, Thordon’s position is that the omission of this text from the VIDA proposal minimises the fact that a current in‐use and proven zero-pollution solution that has no impact on our seas and oceans is likely to be overlooked by vessel operators if it does not appear in the new VIDA.
Using seawater as a stern tube lubricant means there is absolutely zero impact on the ocean and sea environment, as there is no oil or synthetic EAL used. Thordon firmly believes that the recommendation from the US EPA stated in the VGP 2013 – to use the only lubricant that has no impact on the environment and is currently in use in thousands of vessels – is an incredibly powerful statement to eliminate stern tube oil pollution from ships navigating US waters.
Thordon questions why the EPA would want to remove such a statement from the 2013 VGP; it encourages new ships to be built using seawater lubrication. This omission from the Oil Management section would be deemed as going backward, rather than forward.
“A proven, zero-pollution solution that has no impact on our seas and oceans is likely to be overlooked”
The glaring omission is not the only issue with the proposed amendments. A major concern is the confusion surrounding air-type shaft seals.
On page 56 of the proposed draft, it states “during normal operation, small quantities of lubricant oil in these interfaces are released into surrounding waters.” But three pages later it states: “To the extent that these seals do not allow the lubricant to be released under normal circumstances they are not considered to be oil‐to‐sea interfaces.”
These statements do not take into account seal failure resulting from rope or fishing lines becoming entangled around the propeller shaft. Aft seal damage can be severe, creating an oil‐to‐sea interface enabling synthetic lubricant/oil to flow freely out into the ocean. Confusion could also result in ship operators using mineral oil in an air seal, which is worse than an EAL discharge.
Thordon also raises questions about the harmful impact that synthetic/vegetable EALs may have on aquatic life, suggesting that more research needs to be done on their environmental impact before their use can be approved as an EAL.
At the time of writing, www.regulations.gov, the US government website used for public commentary on new and existing regulations, had received 179 comments on the proposed VIDA amendments.